Aerial refueling is commonly employed to increase the range and flight duration of an aircraft. Aerial refueling is typically accomplished by having a tanker aircraft carrying a payload of fuel fly on a specified flight path. A receiving aircraft flies in close proximity to the tanker aircraft, and fuel is transferred from the tanker aircraft to the receiving aircraft via a rearwardly-extending boom. The boom is typically operated by an operator located in the tanker aircraft who maneuvers the boom into temporary engagement with a fuel-receiving port of the receiving aircraft. After a desired quantity of fuel is transferred to the receiving aircraft, the operator disengages the boom from the fuel-receiving port, and the receiving aircraft continues on its designated mission. Known aerial refueling systems include, for example, those systems disclosed by U.S. Pat. No. 5,996,939 issued to Higgs et al., U.S. Pat. No. 5,573,206 issued to Ward, and U.S. Pat. Nos. 4,763,861 and 4,633,376 issued to Newman.
In early aerial refueling systems, the boom operator performed the task of manipulating the boom into the fuel-receiving port by direct observation using the naked eye. In more advanced systems, the boom operator views the boom and receiving aircraft remotely by means of camera(s) positioned on a rearward portion of the tanker aircraft. The camera(s) transmits images to a display or monitor located inside the tanker aircraft, typically in a forward portion of the aircraft.
Although desirable results have been achieved using prior art aerial refueling systems, some drawbacks have been noted. For example, during some operating conditions, aerial refueling operations may be hampered by glints, shadows and glare caused by the sun, atmospheric water vapor, or reflections from aircraft surfaces. These conditions may hamper aerial refueling operations, such as by precluding clear visualization of the fuel-receiving port, and may necessitate a deviation of the tanker aircraft and the receiving aircraft from the planned course into an alternate course that allows the boom operator an improved view of the fuel-receiving receptacle. This may necessitate delays in the refueling process and in the overall mission, resulting in increased demands on the tanker aircraft and the receiving aircraft and their respective crews. Thus, there exists a need for an enhanced viewing system that reduces adverse viewing conditions that may otherwise hamper aerial refueling operations.